/*
 * Copyright 2008,2018 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 *
 * GNU Radio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

/* The path memory for each state is 32 bits. This is slightly shorter
 * than we'd like for K=7, especially since we chain back every 8 bits.
 * But it fits so nicely into a 32-bit machine word...
 */

#ifndef INCLUDED_VITERBI_H
#define INCLUDED_VITERBI_H

#include <gnuradio/fec/api.h>

namespace gr {
  namespace fec {

    struct FEC_API viterbi_state {
      unsigned long path;   /* Decoded path to this state */
      long metric;    /* Cumulative metric to this state */
    };

    FEC_API
      void gen_met(int mettab[2][256],  /* Metric table */
                   int amp,     /* Signal amplitude */
                   double esn0,   /* Es/N0 ratio in dB */
                   double bias,   /* Metric bias */
                   int scale);    /* Scale factor */

    FEC_API unsigned char
      encode(unsigned char *symbols, unsigned char *data,
             unsigned int nbytes,unsigned char encstate);

    FEC_API void
      viterbi_chunks_init(struct viterbi_state* state);

    FEC_API void
      viterbi_butterfly2(unsigned char *symbols, int mettab[2][256],
                         struct viterbi_state *state0, struct viterbi_state *state1);

    FEC_API unsigned char
      viterbi_get_output(struct viterbi_state *state, unsigned char *outbuf);
  }
}

#endif /* INCLUDED_VITERBI_H */
